docs: def update_when_older(self, days):
          """
          Update TLD list cache file if the list is older than
          number of days given in parameter `days` or if does not exist.
  
          :param int days: number of days from last change
          :return: True if update was successful, False otherwise
          :rtype: bool
          """
  
          last_cache = self._get_last_cachefile_modification()
          if last_cache is None:
              return self.update()
  
          time_to_update = last_cache + timedelta(days=days)
  
          if datetime.now() >= time_to_update:
              return self.update()
  
          return True